Kees Cook is part of the Ubuntu Security Team, where he tries to harden Ubuntu in particular, and Linux in general, against attack. In addition to being an Ubuntu developer, he's a member of the Ubuntu Technical Board, a Debian Developer, and a Kernel.org admin. As a long-time DEF CON Capture the Flag participant, he's especially proud of being part of Team 1@stPlace and winning in 2006 and 2007. Twitter: @kees_cook